The present invention relates to an electrical connecting apparatus such as a probe card to be used for an electrical test of an electrical circuit to connect, for example, an integrated circuit as a device under test to a tester that performs an electrical test of it.
As one of the conventional electrical connecting apparatuses of this kind is proposed an electrical connecting apparatus comprising a probe board provided with a plurality of probes and enabling adjustment of the planarity of the probe board Japanese Unexamined Patent Publication No. 2003-528459). With this electrical connecting apparatus, a thrusting force or a tensile force can act from a support member supporting the probe board toward a part of the probe board. Adjustment of this acting force can correct bend and deformation of the probe board even if the probe board is bent to maintain the planarity of the probe board.
Accordingly, since the planarity of the probe board can be maintained by the aforementioned adjustment work after the probe board has been attached to the support member even if the probe board is bent and deformed at the time of manufacture of the probe board provided with the plurality of probes, the tips of the plurality of probes extending from the probe board can be held on the same plane. Thus, since the tips of all the probes can reliably contact electrical connecting terminals, corresponding to the respective probes, of an electrical circuit as a device under test, efficient electrical contact can be attained between them.
However, in the aforementioned prior art described in Japanese Unexamined Patent Publication No. 2003-528459, adjustment is needed every time of the probe board is attached to the support member in accordance with bend and deformation introduced in each probe board so that all the probe tips may be located on the same plane. The adjustment work to let all the probe tips appropriately contact the aforementioned corresponding respective electrical connecting terminals of the device under test in a state where the probe board is attached to the support member is troublesome and requires skills. Especially, in a test of numerous integrated circuits formed on a semiconductor wafer, the number of probes to be provided on the probe board significantly increases. Thus, the adjustment work to let such numerous probes appropriately contact the corresponding respective pads on the semiconductor wafer is not easy.
Under such circumstances, the present applicant proposed in a prior International Patent Application (PCT/JP2005/009812) an electrical connecting apparatus that requires no planarity adjustment work of the probe board after being attached to the support member regardless of the deformation of the probe board and enables reliable electrical connection between the probes and the corresponding electrical connecting terminals of the electrical circuit as a device under test.
In this electrical connecting apparatus, a spacer allowing an attachment bolt to pass therethrough is arranged between the attachment surface of the support member and the probe board so that the tips of the probes provided on the probe board are aligned on the same surface. The tip of this attachment bolt is screwed in a screw hole in a fixed portion formed on an opposite surface of a surface of the probe board on which the probes are provided. The aforementioned spacer acts to keep predetermined space between the attachment surface of the support member and the probe board so that the probe tips are located on the same surface at the time of tightening of the attachment bolt.
Thus, after the probe board is attached to the support member, the tips of all the probes can be thrust to the respective electrical connecting terminals of the electrical circuit as a device under test approximately uniformly without the need for the conventional adjustment work for planarization of the probe board. As a result, the aforementioned conventional troublesome planarity adjustment work is not needed per replacement of the probe board provided with the plurality of probes, which enables an efficient electrical test.
Meanwhile, such a probe board is formed by combining a wiring plate in which wiring paths are formed in a multilayered form and to which the probes are provided per corresponding wiring path with a support plate such as a ceramic plate supporting the wiring plate at the opposite surface of the surface to which the probes are provided. Numerous conductive paths referred to as through holes are formed to pass through the ceramic plate as the support plate of the probe board in the plate thickness direction for electrical paths for the corresponding probes. Also, on the ceramic plate is formed the fixed portion in which the tip of the aforementioned attachment bolt is screwed.
This fixed portion is formed by fixing a female screw member at an area where unnecessary ones out of the through holes or conductive paths formed in the ceramic plate are provided. Accordingly, when a strong tensile force acts on the female screw member forming the fixed portion at the time of and as a result of tightening of the aforementioned attachment bolt, a portion of the ceramic plate fixed by the female screw member is tensed by the female screw member. Since the rim portion of the through hole under the female screw member of the ceramic plate can be a fragile portion of the probe board against this tensile force, heightening of the mechanical strength of the probe board has been desired.